Electronic devices are usually directly wired through a commercial or residential electrical wiring infrastructure, through an electrical power cord, AC adapter or the like. As they are permanently installed, the repositioning of these devices is challenging.
To provide mobility, many portable or handheld devices are powered by conventional or rechargeable batteries. However, the use of batteries often requires increasing the size of an electronic device to allow batteries to be inserted. To alleviate this problem some very low power devices are solar powered, but this requires that a user expose the device to solar energy that may not be available when necessary. Battery powered devices require replacement of the battery.
Consequently, there is a need further to develop wireless energy transmission to be used for energy harvesting to power electronic devices.